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FTB-2 и FTB-2 Pro. Руководство пользователя - часть 25

Data Types

Applicable Data Types for Output —IEEE 488.2

 <HEXADECIMAL NUMERIC RESPONSE DATA>

This data type will be used by a device to return integer representations

in hexadecimal (base 16).

<digit>

Examples: #HA3C5, #H0123C, #H010F

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Data Types

Applicable Data Types for Output —IEEE 488.2

 <OCTAL NUMERIC RESPONSE DATA>

This data type will be used by a device to return integer representations

in octal (base 8).

Examples: #Q753214, #Q0124, #Q0725

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Data Types

Applicable Data Types for Output —IEEE 488.2

 <BINARY NUMERIC RESPONSE DATA>

This data type will be used by a device to return integer representations

in binary (base 2).

Examples: #B11011110101, #B110100, #B0100

 <STRING RESPONSE DATA>

This data type will be used by a device to return strings containing 7-bit

ASCII characters and especially when text has to be displayed since

even the non-printable characters are also returned.

<non-single

quote char>

Examples: "SCPI Commands", "SCPI ""Commands"""

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Data Types

Applicable Data Types for Output —IEEE 488.2

 <DEFINITE LENGTH ARBITRARY BLOCK RESPONSE DATA>

This data type is used by a device to return blocks of 8-bit binary

information with a fixed and predetermined length.

<non-zero

<8-bit data

<digit>

digit>

byte>

The actual length of the retrieved data has the following structure:

 The first byte contains the # character.

 The byte that immediately follows contains the number of

subsequent bytes that you have to check to know the total length.

For example, if you receive this response (here, values are expressed

in decimal instead of binary for easier readability):

# 2 1 3 7 6 8 9 2 ...

The byte that immediately follows the # contains 2, which means that

you have to read the two following bytes to know the length (in bytes)

of the retrieved data. The bytes indicate 1 and 3. The length will then

be 13 bytes. The actual response will begin at byte number 5, in this

case.

Examples: #14<DAB><DAB><DAB><DAB>,

#3004<DAB><DAB><DAB><DAB>

where “<DAB>” stands for data byte

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Data Types

Applicable Data Types for Output —IEEE 488.2

 <INDEFINITE LENGTH ARBITRARY BLOCK RESPONSE DATA>

This data type is used by a device to return blocks of 8-bit binary

information when the block length was not predefined or when data

has to be computed later.

<8-bit data

<RESPONSE MESSAGE

byte>

TERMINATOR>

Note: If you receive a zero as the first digit (#0), it is necessarily followed by a

<RESPONSE PROGRAM MESSAGE TERMINATOR> so that you will detect

the end of the <INDEFINITE LENGTH ARBITRARY BLOCK RESPONSE

DATA>.

Example: #0<DAB><DAB><DAB><DAB><terminator> where

“<DAB>” stands for data byte.

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Data Types

Applicable Data Types for Output —IEEE 488.2

 <SUFFIX RESPONSE DATA>

This data type is used by a device to return units and multipliers.

<digit>

<digit>

Examples: DBW, W, KHZ

 <ARBITRARY ASCII RESPONSE DATA>

This data type is used by a device to return information when it is

impossible to use any other data type.

Example: To the *IDN? query, the device will return this response in an

arbitrary ASCII bytes format:

EXFO E.O. Engineering,,125-2A55,1.0.1.97

<ASCII data

<RESPONSE MESSAGE

by te>

TERMINATOR>

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Data Types

Applicable Data Types for Input—SCPI

SCPI data types include the IEEE 488.2 data types (see Applicable Data

Types for Input—IEEE 488.2 on page 362) with certain additional

restrictions.



<numeric_value>: abbreviated form of the decimal numeric element.

It differs from the <DECIMAL NUMERIC PROGRAM DATA> “<NRf>”

described in IEEE 488.2.

Several forms of <CHARACTER PROGRAM DATA> are defined as

special forms of numbers. These are: MINimum, MAXimum, DEFault,

UP, DOWN, Not A Number (NAN), INFinity and Negative INFinity

(NINF). The following special forms are likely to be used by EXFO’s

instruments in certain commands or queries:



DEFault: This special <numeric_value> parameter forces the

instrument to select a value, which is deemed to be convenient to

the user.



MINimum|MAXimum: These special <numeric_value>

parameters refer to the instrument’s limit values. MINimum

corresponds to the value closest to negative infinity that the

function can accept. MAXimum corresponds to the largest value

that the function can accept.



<Boolean Program Data>: This form is often used as a shorthand

of the <DECIMAL NUMERIC PROGRAM DATA>ON|OFF form.

<Boolean Program Data> parameters have a value of 0 or 1 and

are not followed by any unit.

On input, an <NRf> is rounded to an integer.

A non-zero result is interpreted as 1.

ON and OFF are accepted on input for readability purposes. They

correspond respectively to 1 and 0. However, on output, they

appear as 1 or 0, never ON or OFF.

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Data Types

Special Numeric Values Received on Output

It is possible that an instrument returns unusual values in certain cases. For

information on these values, see Applicable Data Types for Output —IEEE

488.2 on page 371.

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FTB-2 and FTB-2 Pro

C IEEE 488.2 and Specific

Command Reference

This chapter presents detailed information about the commands and

queries supplied with your FTB-2 and FTB-2 Pro.

IEEE 488.2 Commands-Quick Reference

The FTB-2 and FTB-2 Pro recognizes the required commands identified in

IEEE 488.2. The table below summarizes these commands. These

commands are fully explained on the following pages.

Command

Function

*CLS

Clear status command

*ESE

Standard event status enable command

*ESE?

Standard event status enable query

*ESR?

Standard event status register query

*IDN?

Identification query

*OPC

Operation complete command

*OPC?

Operation complete query

*RST

Reset command

*SRE

Service request enable command

*SRE?

Service request enable query

*STB?

Read status byte query

*TST?

Self-test query

*WAI

Wait for pending operations to be completed

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IEEE 488.2 and Specific Command Reference

IEEE 488.2 Required Commands

*CLS

Description

The *CLS command clears the Standard Event

Status Register and the Error/Event Queue.

Syntax

*CLS

Parameter(s)

None

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FTB-2 and FTB-2 Pro

IEEE 488.2 and Specific Command Reference

IEEE 488.2 Required Commands

*ESE

Description

The *ESE command sets the Standard Event

Status Enable Register bits, as defined in the

table below. This register contains a mask value

for the bits to be enabled in the Standard Event

Status Register.

MSB

Standard Event Status Enable Register

LSB

PON

URQ

CME

EXE

DDE

QYE

N.U.

OPC

Syntax

*ESE<wsp><RegisterValue>

Parameter(s)

RegisterValue:

The program data syntax for <RegisterValue> is

defined as a <DECIMAL NUMERIC PROGRAM

DATA> element.

The <RegisterValue>, expressed in base 2,

represents the bit values of the Standard Event

Status Enable Register.

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IEEE 488.2 and Specific Command Reference

IEEE 488.2 Required Commands

*ESE

The table below shows the contents of this

Bit

Weight

Meaning

PON

128

Power ON Enable

URQ

User ReQuest Enable

CMD

CoMmanD Error Enable

EXE

Execution Error Enable

DDE

Device Dependent Error Enable

QRY

QueRry Error Enable

N.U.

Not used

OPC

Operation Complete Enable

A value of 1 in the Enable Register enables the

corresponding bit in the Status Register, a value

of 0 disables the bit. The value of the

<RegisterValue> shall be in the range of 0

through 255.

Example(s)

*ESE 25

where 25 = (bit EXE, bit DDE and bit OPC)

*ESE 0

clears the content of the Standard Event Status

Enable register